Php fpm high cpu usage 300% with one php script

total child p[rocess 40 CPU 300% memory 30% fpm. 4core 8g ram.

WordPress

domain.com/index.php

is this issue caused by a plugin.

reduced child servers same issue.

changed to ondemand.

now only 2 processes are running including active& idle.

cpu usage 3% memory age 8% by php-fpm.

what happened? i have to re-enbale dynamic method for php fools.

after few minutes on demand also using 16 processes all by the same website script among 50 sites.

HungryFEED is the plugin caused 1000+ requests and it longer available in wp plugin directory. deactivated that all processes are back to normal.